Fluid pressure actuated clutch



Jan. 29, i952 W, G, WILSON 2,583,919

FLUID PRESSURE ACTUATED CLUTCH Filed March 18, 1946 2 SHEETSwSI-IEET l Jan. 29, 1952 W. G. WILSON 2,583,919

FLUID PRESSURE ACTUATED CLUTCH Filed March 18, 1946 2 SHEETS--SHEET 2 i 53 5() 5 `5652 57 51 4 H l f 58 49 'Fig.2.

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put shaft 4. From the radial passages 28 the oil flows to the annular space 28a and through holes 36h in the bush 36a.

When the clutch I9 is to be operated it will be appreciated that the pressure uid passing through duct 24 and acting on the relay valve I8 will move the valve axially against the spring when vthe pressureof the iluid is suilicient to overcome the spring. In addition to the pressure set up by the pump there will be an increment owing to the action of centrifugal force. Such increment will howeverbe neutralised by the action of centrifugal force on the oil in the reservoir 2| acting upon the opposite face of the valve |8, so that the valve will operate as determined by the force of the valve spring 20.

The valve I8 is provided withfan annular groove 29 controlling a pair of ports 3U, 3| in the wall of the chamber l1. One of the ports 3| leadsV to atmosphere or the low pressure side and the other 30 is connected by suitable passages or clearances 32 with the .oil in the clutch chamber |33 so that oil from the chamber may pass to the low pressure side when the valve i8 is in the position shown in Figure l.

The oil of thelubricating system which supplies the reservoir 2| flows along splines 33 in the output `shaft and at the'position where the sun pinionli) engages such splines, the splines are partially cut awayat-34 to permit the ow of oil. Adjacent the reservoir a seal 35 is pro vided in the splines and a passage 38 leads from the splines to the hush 36a whence oil escapes via. the running clearances around the bush into reservoir 2|. y

The clutch means comprises a series of plates or discs 31, alternate plates being splined to the shell 1 and to an inner disc 38 which in turn is splined to the adjacent end of the output shaft 4. The outer plates of the series splined the shell 1 are locatedbetween an abutment ring 35 and a disc 40 which is associated with or forms part of the piston element 4| by which the plates are .moved axiallywith preliminary contacting engagement, the piston4l beingoperated bythe pressure fluid passing along the axial bore 21 and radial passages 2B in the output shaft and annular space Zea and passages 36D as referred to above.

In order to spread or openthe plates when the clutch is out corrugated or sinuous spring plate elements 42 are located between the inner y set of clutch plates splined to the disc 38. Similaispring elements 42 may be provided between the outer clutch plates, additionally or alternatively. v The clutch plates may be of the construction according to my concurrent application Serial No. 655,280, iiled March 18, 1946. Thus adjacent their outer peripheries where the clutch -plates 31 ,still overlap one .another V.the surfaces Athe cuter peripheries -owing to irregularities in thesurfacesof the plates is allowed tao-escape and thus an opposing pressure is avoided. The

groovesand` apertures will also collect and disperse any, oil that may percolate between the plates from their inner margins underhe .actionf'ofscentrifugal force.

.l .It .will .beapprweciated thatzthegrooves 1434111@ f be provided on both sets of plates, or alternatively on the inner set.

Figures 2 and 3 showv a modication in which the invention is applied to a hydraulically actuated cone clutch. The input shaft has secured thereon a pair of apertured discs 46 and 41 which are bolted together adjacent their peripheries. The disc 46 -is spigotedinto the disc 41 and the latter is provided with-an -internally coned clutch surface 48 having a friction lining 49. Co-operating with the coned surface 48 is a disc 50 having a coned periphery 5l. The disc 50 is provided with a sleeve 52 entering the aperture 53 in the disc 48 vwith a sliding fit. The disc 50 is also provided with an annular portion 54 which enters a recess 55 in the disc 45 with a slight clearance 58 at its'fperiphery. The space between the annulus 54and the base of the recess 55 forms a primaryI chamber 5B for the pressure fluid by which the clutch member or disc 50 is moved axially. Theangle of the Vconical surfaces 48 and 5| is such thatthey become free on release oi the clutch' applying pressure of the operative fluid.

A second chamber 51' is formed outwardly of the chamber 56 by an annular recess in the disc it. AThis chamber 51 forms a secondary chainber for the pressure ii-uid and communicates with the primary chamber 5B by the clearance 58 and a radial space between the discs 46 and 55.

The output shaft 2 has a boss 6G formed thereon which is provided with teeth or splines 5| meshing with teeth or splines on the movable 'clutch disc 50. The shaft 2 is also provided with a .reduced end or spigot 62 extending through an axial aperture in the sleeve 52. a

The relay valve 53 is located in a bore inthe fdisc 41 adjacent'its periphery and is provided vby a duct '68 and passage` 69 with a reservoir 10 ,formed inthe peripheral wall surrounding the aperture irrthe disc 41.` Thev reservoir 10' is adapted to'receive oil from the lubrication system. The depth of oil in the reservoir remains constant as any excess-oil flows freely over the lips 1| to the low pressure side.

The passage 55 isr closed at its outer end by a screwed plug a. The passage 69 is closed beyond the passage 58 by thepin 64a which guides the spring 64'. j

. Oil is-deliveredV to the reservoir by a duct 12 in the boss 5G which isconnected by an annular ,passage 13 extending through the output shaft 2 and communicating -with a supply.

Pressure viiuid ows to the primary chamber 56 by way of the duct 14,V dishing 15 in theend of the input shaft and an axial bore 16 in the output'shait.

The valve B3 is provided with an annular recess 11 adaptedA when the clutch is in the foif" position (see Figure) to allow oiljin the chamber 51 to pass through the'passage A|51 and passage 18 tothe lowpressure side-' .g

When the clutch -is-to-bev puton oil owing into the primary chamber 5 .passesfalong --the passages v65, 66 and-aci'lsjon the valve T63 .against the.aeti9r 1 9f 6s; ifftbqfprsulfi-Qffilie 9114.5

suillcient to overcome the spring 64 the valve will move to close the outlet 61, 18 to the low pressure side.

clutching engagement with clutch cones 48, 49.

Centrifugal force on the pressure fluid acting Pressure will thus be built up in the chamber 58 to move the clutch disc 50 into on the valve is balanced by centrifugal force on the oil in the reservoir '10, acting through passage 69 on the opposite end of the valve.

The pressure fluid is supplied from a pump through the conduit 19 under control of a valvejf 80 and passes through a radial passage 8| to the-v bore 16. The lubricating oil is by-passed from the conduit 'I9 through passages 82, 83 to the annular passage 13 under control of a pressure regulator 84.

The valve 80 is arranged to shut off the supply of oil from conduit 19 when moved to the oif"` ;r

position and at the same time to release to atmosphere, or to the low pressure side, any pressure remaining in passages 8| and 'I6 so that Y the relay valve moves under the action of spring 64 to the off position and allows the oil to escape from chamber 51 through passages 61 and 18 to the low pressure side.

It is to be noted that the improved relay valve arrangement may be used with any form of hyr draulic clutch or other appropriate hydraulic mechanism in which centrifugal force produces a actuated piston in the cylinder for operating the l clutch mechanism, means to supply an operating fluid under pressure to said piston, valve relay.:4 means for controlling the ilow of the operating'-`v uid to said piston .such that actuation of the I clutch mechanism cannot be effected until the pressure of the operating fluid attains a predeg:K termined amount suillcient to actuate the relay valve means to move it to a position which allows the operating fluid to act upon said piston, means defining a chamber, further means to supply Vfluid to said chamber, which fluid forms a fluid` reservoir having a constant head, means defining` a fluid connection transverse to the axis of ro-ik tation between said chamber and the relay valve means so that the fluid in said chamber acts upon;rk said valve in opposition to the operating iluid during an operative period, whereby substantially equal and opposite forces set up by centrifugal action on the operating fluid and the f luidjin said chamber act upon the valve relay means during the operative period. l

2. Hydraulic clutch mechanism as claimedin claim 1, wherein the valve relay means comprises a reciprocating valve mounted with its axis of reciprocation parallel to the axis of revolution of the clutch mechanism.

3. Hydraulic clutch mechanism as claimed in claim 1, wherein the valve relay means comprises a reciprocating valve mounted with its axis of reciprocation parallel to the axis of revolution of the clutch mechanism, a lubricating system for conveying lubricating oil to the operative parts of the clutch mechanism, said chamber comprising an annular cavity in a rotary part of the clutch mechanism, a passage for conveying lubricating oil from said system to said cavity to provide the fluid reservoir, and an overflow passage from the cavity whereby a constant head of oil is maintained in the chamber.

4. Hydraulic clutch mechanism comprising input and output elements, intermeshing clutch plates connected alternately to the input and output elements, a cylinder, a pressure iluid actuated piston in the cylinder for moving said plates to their clutching position, means for supplying an operating fluid under pressure` to said piston, a reciprocating relay valve for controlling the flow of pressure fluid to said piston whereby the actuation of the clutch mechanism cannot be effected until the pressure of the operating fluid attains a predetermined amount suilicient to actuate the relay valve, said valve being arranged with its axis parallel to the axis of revolution of the clutch, means deiining an annular cavity in a rotary part of the clutch mechanism forming a chamber, means to supply fluid to said chamber to form a iluid reservoir having a constant head, means deiining a fluid path transverse to the axis of rotation between said chamber and the relay valve so that fluid in said chamber acts upon said valve in opposition to the operating fluid during an operating period, whereby substantially equal and opposite forces set up by centrifugal action on said operating uid and the fluid in said chamber act upon the valve during the operating periodg WALTER GORDON l/VILSON.

REFERENCES CITED UNITED STATES PATENTS Number Name Date 1,380,823 Matthews et al. J-une 7, 1921 1,938,914 Kress Dec. 12, 1933 2,163,202 Kegresse June 20, 1939 2,178,017 Fedden et al Oct. 3l, 1939 2,217,357 Coe Oct. 8, 1940 2,245,857 Hale June 17, 1941 2,399,853 Chilton May 7, 1946 

